The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art to the present technology.
An alkyd is a polyester modified by the addition of fatty acids and other components. Alkyd resins are commonly used as binders for ambient-cure, solvent-based coatings. The curing of solvent-borne alkyd resins is accomplished via autooxidative crosslinking of the alkyd film. Crosslinking occurs when the activated methylene groups in the unsaturated fatty acids or oils of the alkyd are oxidized in air to give hydroperoxides which subsequently decompose to generate free radicals, resulting in oxidative crosslinking. This oxidative crosslinking process is commonly accelerated by adding driers, such as, for example, various salts of cobalt, zirconium, calcium, and manganese. Although useful, most alkyd resins are poorly biodegradable and potentially harmful to the environment. Consequently, there is a need among producers of the alkyd resins for improved coatings that satisfy consumer needs but are non-toxic and biodegradable.